Electrically conductive room temperature curable compositions are described in U.S. Pat. No. 4,011,360 to Walsh, in which the composition contains a linear siloxane polymer of the formula R'R.sub.2 SiO(R.sub.2 SiO).sub.x SiR.sub.2 R', where R is a monovalent hydrocarbon radical and each R' is a hydrogen atom, alkoxy radical, aryloxy radical, hydroxyl radical or acyloxy group and x is an average of from 50 to 10,000, an aminosilane or aminosilazane and electrically conductive particles containing a glass, ceramic and plastic core, which is coated with a noble metal.
Electrically conductive organopolysiloxane compositions are also described in U.S. Pat. No. 4,273,697 to Sumimura et al in which the composition contains (A) 100 parts of a curable liquid organopolysiloxane, (B) from 0.1 to 70 parts by weight of carbon black having a specific surface area of at least 900 m.sup.2 /g, (C) from 0 to 50 parts by weight of a hydroxyl endblocked polydiorganosiloxane whose degree of polymerization is 50 or less, and (D) a cross-linking agent for the curable organopolysiloxane.
Also, U.S. Pat. No. 4,250,075 to Monroe et al discloses electrically conductive compositions containing (A) vinyldiorganosiloxy endblocked polydiorganosiloxanes, (B) carbonaceous particles having an average diameter of less than 20 micrometers, (C) a polyorganohydrogensiloxane having an average of at least 2.1 silicon-bonded hydrogen atoms per molecule, (D) a platinum containing catalyst, and (E) a platinum catalyst inhibitor, in which at least 2 percent by weight of phenyl radicals are present based on the weight of the cured composition.
It has been found that when the electrically conductive curable organopolysiloxane compositions of the present invention contain silver coated mica, the compositions have a tendency to separate into two phases, an oily phase and a solid phase, and they are no longer thixotropic.
Therefore, it is an object of the present invention to provide electrically conductive organopolysiloxane compositions. Another object of the present invention is to provide room temperature vulcanizable electrically conductive compositions. A further object of the present invention is to provide electrically conductive curable organopolysiloxane compositions which are homogeneous. A still further object of the present invention is to provide a process for preparing stable electrically conductive curable organopolysiloxane compositions.